Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.4.21.4 (trypsin)
42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Substitution of casein by proteins of milk serum or by bovine blood serum albumin in the diet of 15 days old rats, maintained on artificial food, led to a 2-3-fold increase in the rate of transport of alimentary protein from stomach and to a corresponding elevation in content of nitrogen containing material in chymus of the small intestine. Distinct activation of trypsin and chymotrypsin as well as an increase in concentration of low molecular products of the protein proteolysis were found in the chymus of small intestine.
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PMID:[Digestion of incoagulable proteins during the early postnatal period of development]. 745 63

It was the purpose of this study to define whether trypsin inhibitors impair protein digestibility via enhanced loss of exogenous or endogenous protein by quantifying those losses using the homoarginine technique, recently developed in this laboratory. Pigs fitted with permanent ileal T-cannulas were fed test meals containing homoarginine-labeled protein. The meals contained casein and increasing doses of trypsin inhibitors (Experiment 1) or alternatively either heat-treated or raw ground soybeans (Experiment 2). Following a casein meal (425 mmol nitrogen, no trypsin inhibitors), ileal protein was predominantly of endogenous rather than of exogenous origin (105 vs. 9 mmol nitrogen). Addition of isolated trypsin inhibitors (3000 mg) enhanced appearance of both endogenous and exogenous protein at the ileum (by 73 and 9 mmol nitrogen, respectively). Feeding raw instead of heat-treated soybeans in one single test meal caused a significant increase of endogenous protein from 217 +/- 42 to 263 +/- 47 mmol (mean +/- SEM) and of exogenous protein from 16 +/- 3 to 48 +/- 14 mmol. If fed continuously for 1 wk, a raw soybean diet caused endogenous protein loss to rise significantly from 221 +/- 26 to 432 +/- 85 mmol. We conclude that ingestion of food containing trypsin inhibitor affects nitrogen balance more by losses of amino acids of endogenous secreta than by losses of dietary amino acids.
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PMID:Soybean trypsin inhibitor(s) reduce absorption of exogenous and increase loss of endogenous protein in miniature pigs. 750 18

Higher nitrogen and lipid digestibilities have been obtained with diets containing cottonseed flour rather than soybean flour. To explain these results, in vitro studies were carried out to compare the effects of raw and heated glandless (without gossypol) cottonseed flours versus soybean flours on pancreatic digestive enzyme activities. These effects were compared with those obtained without addition of flour in standard assays. Apparent lipase (lipase colipase dependent) and potential lipase (lipase with saturating amounts of colipase), colipase, phospholipase A2, amylase, trypsin and chymotrypsin activities were measured on specific substrates. Phospholipase A2 and amylase activities were enhanced, while chymotrypsin activity was diminished with both raw and heated flours. Compared with raw and heated soybean flours, raw and heated cottonseed flours promoted higher potential lipase, chymotrypsin, trypsin and lipase activities. Heat treatment of cottonseed flour enhanced apparent lipase, colipase, chymotrypsin, trypsin activities and diminished potential lipase, phospholipase A2 and amylase activities. When soybean flour was heated, apparent lipase, phospholipase A2, chymotrypsin, trypsin and amylase activities were raised while those of potential lipase were decreased. Our findings show that in vitro raw or heated cottonseed flours affect less digestive enzymes than raw or heated soybean flours, apparent lipase activity excepted. Moreover, only chymotrypsin activities were seriously lowered with both flours, especially with raw soybean flour. Hypotheses are suggested to account for the differences in alterations.
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PMID:In vitro rat pancreatic digestive enzyme activities and raw and heated glandless cottonseed and soybean flours. 753 15

Day-old male meat-type chicks were fed a commercial starter diet supplemented with 2 levels of enzyme preparations containing amylase and proteases up to 14 d of age. Enzyme supplementation had no significant effect on feed intake or growth rate, and was accompanied by a significant decrease in gizzard content and small intestine weight. The intestine contents increased and this increase was accompanied by a significant decrease in its pH. Enzyme supplementation depressed the activity of chymotrypsin in the pancreas and the activity of amylase, trypsin and chymotrypsin in the intestinal contents. Some carry-over effects were observed on d 42, 4 weeks after the cessation of the enzyme supplements. These were mainly a significant depression in the activity of trypsin in the intestinal contents. In a balance study, diets supplemented with 0,250 and 1,000 micrograms/kg enzyme preparations were supplied. Exogenous enzyme supplements had no significant effect on the digestibility of all the nutrients studied except for the highest level of enzyme supplementation, which improved slightly but consistently the digestibility of amino acids. Some age effects were observed, mainly a decrease in the digestibility of fat and starch, and in the ME of the diet from weeks 1 to 2 followed by an increase during week 3. Protein digestibility and retention of nitrogen decreased with age.
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PMID:Effect of age and exogenous amylase and protease on development of the digestive tract, pancreatic enzyme activities and digestibility of nutrients in young meat-type chicks. 753 5

Four barrows, initial wt. 70 kg, fitted with permanent pancreatic cannulas according to the "Pouch Method", were used to investigate the effect of dietary inclusion of pectin on pancreatic secretions. The pigs were fed two corn starch-based diets, containing 16% crude protein from soybean meal, with 0 or 7.5% pectin. The pigs were fed twice daily, at 08:30 and 20:30, 900 g each meal. Pancreatic juice was collected continuously at 1-h intervals for a total of 24 h. The inclusion of pectin did not affect (p > .05) the flow of pancreatic juice and the total secretion of nitrogen, lipase, trypsin and chymotrypsin. However, there was a significant (p < .05) decrease in the secretion of alpha-amylase, which was actually a direct result of the replacement of starch by pectin.
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PMID:Exocrine pancreatic secretions in pigs as influenced by the source of carbohydrate in the diet. 769 Oct 18

Digestion, enzyme secretion and intestinal rate of passage were determined in broiler chicks from hatch until 21 d using 141Ce as a nonabsorbed reference substance. Body weight and feed intake increased more rapidly after 10 d posthatch, and, in parallel, time of passage of feed through the intestines decreased by approximately 33%. Net duodenal secretion of amylase, trypsin, and lipase was low at 4 d and increased 100-, 50-, and 20-fold, respectively, by 21 d. Enzyme activity decreased distally in the small intestine. This change was greater with age. The contribution of the ileum to fatty acid absorption decreased after 7 d. Small intestine digestion of nitrogen increased from 78% at 4 d to 92% at 21 d, whereas fatty acid and starch digestion ranged from 82 to 89% in this period. It appears that digestibilities of starch and lipids are not limiting factors in the growth of young chicks.
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PMID:Digestion and absorption in the young chick. 772 61

The production of extracellular inhibitors of papain and trypsin by Streptomyces sp. 22 was studied under different cultural conditions including complex and defined media, temperatures ranging from 18 degrees C to 37 degrees C and a variety of sole carbon and nitrogen sources. In complex nutritionally rich medium, maximal specific growth rates were obtained at 37 degrees C, whereas the highest specific production rates for both papain and trypsin inhibitors were registered at 18 degrees C. Studies on the effect of different carbon and nitrogen sources in defined media underline the importance of the nitrogen source as a strong regulator of the biosynthesis of both inhibitors. Enhanced formation of the inhibitory compounds occurred in the presence of casein. The dynamics of the formation of both inhibitors in defined media showed close association with growth. However, a partial separation of production phases for papain and trypsin inhibitors was observed in complex medium. The results imply differences in the regulation of biosynthesis of the two inhibitors.
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PMID:Biosynthesis of extracellular low-molecular-mass papain and trypsin inhibitors by Streptomyces sp. 22: effect of cultural conditions. 776 26

Streptomyces exfoliatus SMF13 produced leupeptin, chymotrypsin-like protease (CTP), metalloprotease, and trypsin-like protease (TLP) extracellularly. The activity of TLP was specifically inhibited by leupeptin. Production of leupeptin was closely associated with growth but leupeptin was inactivated by leupeptin-inactivating protein (LIP) when growth reached the stationary phase in submerged cultures, or when aerial mycelia started to form on surface cultures. Autolysis of mycelia after the stationary phase in submerged cultures was apparently retarded by the addition of leupeptin; on surface cultures, aerial mycelium formation was clearly retarded by the addition of leupeptin. We propose that CTP participates primarily in utilization of a proteinaceous nitrogen source, that TLP functions as an essential enzyme involved in the metabolism of mycelial protein, that leupeptin inhibits the activity of TLP and that LIP inactivates leupeptin. The cascade of regulatory actions of the compounds, which are produced sequentially during mycelium development, may provide selective advantages in adverse culture conditions.
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PMID:Physiological roles of leupeptin and extracellular proteases in mycelium development of Streptomyces exfoliatus SMF13. 777 79

The insect pathogenic fungus Metarhizium anisopliae produces several extracellular cuticle-degrading proteases and evidence is consistent with one of these, PR1, which is a chymoelastase, being a determinant of pathogenicity. We have shown previously that PR1 production is regulated by both carbon catabolite and nitrogen metabolite repression and also by specific induction under derepressed conditions by insect cuticle. In the present work we have established that an enzymically released proteinaceous component(s) of insect cuticle is capable of inducing PR1 (based on appearance of extracellular activity). Cuticle of the desert locust Schistocerca gregaria treated with KOH to remove protein failed to induce PR1 production, whereas cuticle treated with either chloroform or ether to remove lipids still induced PR1. Cuticle digested with either PR1 or the trypsin-like PR2 of M. anisopliae released peptides mainly in the range 150-2000 Da; addition of these peptides generated by PR1 or PR2 at 3 micrograms alanine equivalents ml-1 induced PR1 production to a level similar (75%) to that obtained with untreated insect cuticle. Several amino acids and peptides which are abundant in insect cuticular protein (Ala, Gly, Ala-Ala, Ala-Ala-Ala, Ala-Pro and Pro-Ala) were tested at a range of concentrations and in restricted cultures for their ability to induce PR1. None induced the protease to the levels seen with cuticle or peptides enzymically released from cuticle, although some dimers and notably the monomers Ala and Gly gave 2-2.7-fold enhanced PR1 activity above depressed basal levels (up to 48-57% of that achieved with induced synthesis on cuticle).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Partial characterization of specific inducers of a cuticle-degrading protease from the insect pathogenic fungus Metarhizium anisopliae. 781 55

The influence of three different feeding regimens on the activities of pancreatic lipase and trypsin in duodenal aspirates and on fecal nitrogen and fat excretion was studied in 35 healthy preterm infants after a 2-wk feeding period. Eleven infants received a standard preterm formula (without long-chain polyunsaturated fatty acids), 12 were fed with an experimental formula that only differed from the standard formula in fat blend composition (with long-chain polyunsaturated fatty acids), and 12 infants received human milk fortified with protein and energy to have similar nitrogen and energy contents as the two formulas. There were no significant differences in duodenal trypsin activities among the groups. In the group fed the standard formula, lipase activity was significantly lower than in the group fed the experimental formula (standard formula group: 8.4 +/- 3.5 kU/L; experimental formula group: 13.8 +/- 4.8 kU/L; P < 0.05) but there was no significant difference between the experimental formula group and the human milk group (15.1 +/- 4.2 kU/L). Fecal nitrogen as well as fat excretion were similar in the three feeding groups. The data suggest that dietary fat composition can influence the postnatal development of duodenal lipase activity in preterm infants.
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PMID:Activities of trypsin and lipase in duodenal aspirates of preterm infants: influence of dietary protein and fat composition. 787 15


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